Questions and Answers Regarding the Utah Population of the Gila Monster Petition Finding

What are the conclusions of the U.S. Fish and Wildlife Service regarding the petition to list the Utah population of the Gila monster? The Service completed a 90-day petition finding for the Utah population of the Gila monster. After evaluating all of the scientific information described or cited in the petition and information readily available in our files, we concluded that the petitioners did not provide substantial information indicating that the Utah population is a distinct population segment (DPS). However, we will continue to work with our partners to conserve and protect Gila monsters across the species’ range.

What is a 90-day finding? The ESA provides for citizens to petition the Service to take listing actions, including adding species to the lists of threatened and endangered wildlife and plants as well as removing species from the lists. The Service is required to make a 90-day finding on whether the petition presents substantial information that the petitioned action may be warranted. That finding is to be made within 90 days, to the maximum extent practicable, after receipt of the petition and is to be published in the Federal Register.

Findings are based on information contained in the petition, supporting information submitted with the petition, and other information available in our files at the time.

A 90-day finding is an initial review to determine whether or not a petition presents substantial information indicating that listing might be warranted under the ESA, thereby necessitating a full status review of the species. The standard for “substantial information” is the amount of information that, when reasonably viewed in light of all information available in the petition and in our files, tends to show that the listing action may be warranted. What specifically does the Service look at to determine if listing may be warranted? The petitioners requested that we list the Utah population of the Gila monster as an endangered or threatened DPS. We first must determine if the population meets our definition of a DPS before we determine its conservation status. Under our DPS policy, we consider whether the population segment is both discrete in relation to the remainder of the species, and whether it is significant to the species to which it belongs. If both of these criteria are met, we then evaluate the population segment’s conservation status in relation to the five factors specified in the ESA. The petitioners did not present substantial information, nor did we have any available in our files, indicating that the Utah population was discrete or significant. Since neither the discreteness nor significance criteria were met, the Utah population cannot be characterized as a DPS. Therefore, we did not evaluate the information contained in the petition regarding the conservation status of the species as it pertains to the five listing factors described in the Act.

How did the Service evaluate discreteness? We concluded that the petition did not present substantial information that the Utah population was discrete in relation to the remainder of the species because: (1) there is a patchy, but contiguous distribution of Gila monsters between Utah and the adjoining States of Arizona and Nevada; (2) there are similar physiological and behavioral characteristics of Gila monsters throughout the species’ range; and (3) there are similar ecological characteristics between Mohave Desert populations in Utah, Arizona, California, and Nevada. How did the Service evaluate significance? We concluded that the petition did not present substantial information that the Utah population was significant to the species as a whole according to the criteria established in our DPS policy because: (1) the ecological setting within which the Utah population resides (i.e., the Mohave Desert) is not unique to Utah; (2) Utah contains less than one percent of the species’ total range; (3) the Utah population is not the only surviving natural occurrence of the species; and (4) the Utah population does not differ markedly from other populations with respect to genetic characteristics. If the species is not warranted for listing, does this mean that conservation efforts are not important? No. The Service will continue to work cooperatively with other federal, state, and private entities to conserve Gila monsters throughout the species’ range. Examples of cooperative efforts include establishment and educational outreach associated with the Red Cliffs Desert Reserve in Utah; development of Habitat Conservation Plans in Utah and Nevada; and development of a Candidate Conservation Agreement in Nevada. All of these cooperative efforts note the Gila monster as one of the species of concern that will be protected by the conservation of Mohave Desert habitat.

What do Gila monsters look like?

The Gila monster is the largest native species of lizard in the U.S. Adults typically have a body length of 12-14 inches. The tail is an additional 6-7 inches long. The Gila monster has rounded beadlike bony deposits on the back of its head, limbs, body, and tail; and a distinctive color pattern of black bands on a pale yellow or orange background on the body and tail. It has a massive skull, venom glands in the lower jaw, and a dark, forked tongue.

Is the Gila monster poisonous?

Yes. The Gila monster is one of only a few known species of venomous lizard, out of approximately 4,000 species of lizards worldwide. The Gila monster does not appear to inject venom into prey; instead, it most likely uses its venomous bite as a defense mechanism. There are no documented cases of human mortality due to its bite. Several components found in the venom of Gila monsters have valuable research and pharmacological applications including the treatment of Type 2 diabetes and possibly memory disorders such as Alzheimer’s disease.

What do Gila monsters prey upon? Gila monsters are slow-moving lizards that depend almost solely on vertebrate eggs and young in nests for food. They can ingest large quantities of prey (up to one-third of their body weight) during a single feeding, and three large meals can supply the yearly energy demands of an adult.

Where are Gila monsters found?

The Gila monster is found in portions of the Mohave Desert in southwestern Utah, southeastern Nevada, southeastern California, and northwestern Arizona; in the Sonoran Desert in southwestern Arizona and Sonora, Mexico; and in small portions of the Chihuahuan Desert in southeastern Arizona and southwestern New Mexico. In Utah, it is found only in the southern portion of Washington County, which comprises less than one percent of the species’ total range.

What type of habitat does the Gila monster use?

The Gila monster favors rocky slopes, washes, and sandy valleys, with sites available for protection from weather extremes and predators. It typically spends more than 95 percent of its time in underground shelters.

How many Gila monsters are there?

The Gila monster is secretive and therefore difficult to accurately count. The total population size is unknown, but the most recent information available indicates that there are probably at least several thousand adult Gila monsters rangewide and possibly 450-800 individuals in Utah. The current population trend is suspected to be declining throughout the U.S., including Utah.